fix(player): 键盘收起后保持评论输入弹窗位置

lib/pages/player/widgets/comment_composer_sheet.dart

@@ -39,6 +39,7 @@ class _CommentComposerSheetState extends State<CommentComposerSheet> {
   final _input = TextEditingController();
   final _inputFocus = FocusNode();
   final _keyboardInset = KeyboardInsetNotifier.instance;
+  double _pinnedKeyboardInset = 0;
   bool _closing = false;
 
   @override
@@ -114,7 +115,8 @@ class _CommentComposerSheetState extends State<CommentComposerSheet> {
 
   @override
   Widget build(BuildContext context) {
-    final keyboardHeight = _keyboardHeight(context);
+    final currentKeyboardInset = _keyboardHeight(context);
+    _pinnedKeyboardInset = math.max(_pinnedKeyboardInset, currentKeyboardInset);
     final l10n = AppLocalizations.of(context)!;
     final signedIn = context.watch<AuthController>().isSignedIn;
     final hasContent = _input.text.trim().isNotEmpty;
@@ -139,7 +141,7 @@ class _CommentComposerSheetState extends State<CommentComposerSheet> {
           child: AnimatedPadding(
             duration: const Duration(milliseconds: 200),
             curve: Curves.easeOut,
-            padding: EdgeInsets.only(bottom: keyboardHeight),
+            padding: EdgeInsets.only(bottom: _pinnedKeyboardInset),
             child: GestureDetector(
               behavior: HitTestBehavior.opaque,
               onTap: () {},

test/comment/drama_comments_sheet_test.dart

@@ -377,8 +377,9 @@ void main() {
     tester.view.viewInsets = const FakeViewPadding(bottom: 180);
     await tester.pump();
     await tester.pump(const Duration(milliseconds: 200));
+    final keyboardUpBottom = tester.getBottomLeft(composer).dy;
     expect(tester.getSize(composer).height, closeTo(compactHeight, 0.1));
-    expect(tester.getBottomLeft(composer).dy, closeTo(844 - 180, 0.1));
+    expect(keyboardUpBottom, closeTo(844 - 180, 0.1));
     expect(
       tester.getBottomLeft(composerInput).dy,
       lessThanOrEqualTo(844 - 180),
@@ -388,12 +389,21 @@ void main() {
     tester.view.viewInsets = const FakeViewPadding();
     await tester.pumpAndSettle();
     expect(composer, findsOneWidget);
-    expect(tester.getBottomLeft(composer).dy, closeTo(844, 0.1));
+    expect(tester.getBottomLeft(composer).dy, closeTo(keyboardUpBottom, 0.1));
     expect(commentsSheet, findsOneWidget);
     expect(list, findsOneWidget);
     expect(placeholder, findsOneWidget);
     expect(tester.getRect(commentsSheet), sheetRect);
     expect(tester.getSize(commentsSheet).height, closeTo(sheetHeight, 0.1));
+
+    await tester.tapAt(const Offset(20, 20));
+    await tester.pumpAndSettle();
+    expect(composer, findsNothing);
+
+    await tester.tap(placeholder);
+    await tester.pumpAndSettle();
+    expect(composer, findsOneWidget);
+    expect(tester.getBottomLeft(composer).dy, closeTo(844, 0.1));
   });
 
   testWidgets('should_keep_composer_open_after_input_loses_focus', (